The field of the disclosure relates generally to wind turbine power generation and more specifically to improving wind turbine efficiency by reducing power losses present in a wind turbine power converter.
A wind turbine uses wind to generate electricity. A wind turbine typically includes a nacelle that houses an electric generator. The wind turbine also typically includes a rotor that includes a plurality of rotor blades attached to a rotating hub. The wind turbine rotor is coupled to the electric generator, wherein the wind turbine rotor converts wind energy into rotational energy that is used to rotate a rotor of the electric generator. Variable speed operation of the wind turbine facilitates enhanced capture of energy by the turbine when compared to a constant speed operation of the turbine. However, variable speed operation of the wind turbine produces electricity having varying voltage and/or frequency. More specifically, the frequency of the electricity generated by the variable speed wind turbine is proportional to the speed of rotation of the rotor. A power converter may be coupled between the electric generator and a utility grid. The power converter outputs electricity having a fixed voltage and frequency for delivery on the utility grid.
Some known power converters include semiconductor switches capable of handling high currents and voltages. Typically, rapid switching of the semiconductor switches is beneficial to the quality of the power output of the converter. However, the semiconductor switches may not be able to operate at high frequencies due to thermal limitations. To overcome the thermal limitations, a filter and a choke may be coupled to the output of the semiconductor switches to filter harmonic content from the electricity. Such filtering may adversely impact the efficiency of the power converters.